Improvement in steam-gages



C. BARNES.

Steam Gage.

No. 49,961. A Patented Sept. 19, 1865.

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UNITED STATES PATENT OFFICE.

CHARLES BARNES, OF CINCINNATI, OHIO.

IMPROVEMENT IN STEAM-GAGES.

Specification forming part ot' Letters Patent No. 49,961, dated September 19, 1665.

To all whom t may concern:

Be it known that I, CHARLES BARNES, of Cincinnati, Hamilton county, Ohio, have invented a new and useful Improvement in Steam- Gages; and I do hereby declare the following to be a full, clear, and exact description thereoi", reference being had to the accompanying drawings, making part ot' this specication.

My invention relates to a construction ot gage capable ot' indicating upon a single dial the entire range of pressures combined with extreme sensitiveness under a light pressure without the liability to disagreementot` dial indications with the actual pressure by giving way ot' the spring in active use.

Figure l is a iront elevation, partly in seetion, of a gage embodying my improvements. Fig. 2 represents the two members ofmy oompound spring detached.

A represents a pipe, which proceeds from the steam-space ot a boiler.

B is a flaring joint-piece or coupling, whose internally screw-threaded rim I) receives the correspondingly screw-threaded hollow stem C, which supports the dial D.

Securely grasped between the coupling B and the stem C is an india-rubber diaphragm, E, upon which rests a disk, F, which supports an exterior and highly-sensitive spring, Gr, and an interior and stiffer and somewhat shorter spring, H. Up to a pressure of about forty pounds upon the square inch, only the longer and more sensitive spring, G, presses against the upper end of the hollow stem C, at which point the inner land stiffer spring H begins to bear. Byproviding in this way two or more concentric helical springs of unequal and gradually -increasing resistance, I am enabled to combine extreme sensitiveness of indication for low pressures with an adequate indication of high pressures in the compass of a single dial.

The. disk F carries two bosses, I and J, which t within the lower ends ofthe springs G and H, respectively.

Secured to the box J is a rod, K, whose upper extremity is pivoted to an arm, L, upon a segment-rack, M, which gears within a pinion, N, upon the shat't ofthe index-hand O.

It will be seen that by employing a series ot' springs acting in succession the strain is so divided as not to sensibly impair the tensional force of any one, as is commonly the case after a brief use where a single spring is required to serve for the entire range of pressures.

I claim herein as new and of my invention- 'Ihe provision in a steam-gage of two or more springs, Gr H, ot unequal tension, arranged and operating' in the manner and for the purpose set forth.

In testimony of which invention I hereunto set my hand.

CHARLES BARNES.

lVitnesses:

GEO. H. KNIGHT, JAMES H. LAYMAN. 

